Gait evaluation of new powered knee–ankle–foot orthosis in able-bodied persons: A pilot study

Background: Knee–ankle–foot orthoses are utilized for walking by patients with lower limb weakness. However, they may be rejected by patients due to the lack of knee flexion available when using them for walking activities. Aim: The aim of this study was to perform a pilot study investigating the effect of a new powered knee–ankle–foot orthosis on walking in healthy persons before testing with patients with lower limb weakness. Methods: Walking evaluation was performed on five healthy subjects (mean age: 26 ± 5.6 years). Walking trials were randomly performed in three test conditions: normal walking without an orthosis, walking with a conventional knee–ankle–foot orthosis unilaterally, and also with a new powered knee–ankle–foot orthosis applied to the same leg. Results: The means of walking speed, cadence, and knee flexion during swing and step length were all decreased. Compensatory motions were increased by both orthoses compared to normal walking. More knee flexion was observed in both swing and stance phases when walking with the powered knee–ankle–foot orthosis compared to the conventional knee–ankle–foot orthosis. Conclusion: The results demonstrated the potential of a powered orthosis in providing improvements in gait parameters compared to a conventional device in healthy subjects but are yet untested in subjects with lower limb weakness. Clinical relevance The results of this study demonstrated that a powered knee–ankle–foot orthosis could lock the knee during stance and provide active knee flexion during swing to potentially reduce the tripping during ambulation.